"Voices in the Dark" starts with the destruction of Babylon 5 in 2282, as seen in "Sleeping in Light".

True, true... but that's really in there only to avoid confusing the audience, who've already seen "Sleeping in Light." A simple narrative method to remind the audience "we're going backwards by a number of years."

That's different than the way that "In the Beginning" handled it, where the entire story is set in the later time... in the form of Londo telling a story. The entire story is told from Londo's perspective, with Londo narrating it.

So I tend to disregard that little opening "splash" to the "Lost Tales" episode you mention. Ideally, I'd prefer the whole "Lost Tales" thing to not have that opening at all... but then again, SOME people would, inevitably, be confused by that!